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A225068 Least octagonal (8-gonal) number that is the product of n octagonal numbers greater than 1. 1
8, 1408, 2165800, 37333296, 19384601600, 69370076160, 69370076160, 56288711711232000, 7917914554368000000, 199449790781142859776 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..10.

Lars Blomberg, Table of n, a(n) with solutions for n=1..10

EXAMPLE

Let oct(n) = n*(3n-2). Then

a(1) = 8 = oct(2).

a(2) = 1408 = oct(22) = oct(2) * oct(8).

a(3) = 2165800 = oct(850) = oct(4) * oct(5) * oct(17).

a(4) = 37333296 = oct(3528) = oct(3)^2 * oct(8) * oct(13).

a(5) = 19384601600 = oct(80384) = oct(2)^2 * oct(5) * oct(14) * oct(53).

a(6) = 69370076160 = oct(152064) = oct(3)^3 * oct(4) * oct(7) * oct(22).

CROSSREFS

Cf. A000567 (octagonal numbers).

Cf. A212616, A212617, A225066-A225070 (3-, 5- to 10-gonal cases).

Sequence in context: A283902 A064073 A282889 * A270145 A201492 A172938

Adjacent sequences:  A225065 A225066 A225067 * A225069 A225070 A225071

KEYWORD

nonn,more

AUTHOR

T. D. Noe, May 01 2013

EXTENSIONS

Corrected a(4) and added a(7)-a(10) by Lars Blomberg, Sep 21 2013

STATUS

approved

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Last modified September 18 12:00 EDT 2019. Contains 327170 sequences. (Running on oeis4.)